From owner-cvs-all@FreeBSD.ORG  Fri Dec  5 22:54:57 2003
Return-Path: <owner-cvs-all@FreeBSD.ORG>
Delivered-To: cvs-all@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 588E916A4D0
	for <cvs-all@FreeBSD.org>; Fri,  5 Dec 2003 22:54:57 -0800 (PST)
Received: from relay.pair.com (relay.pair.com [209.68.1.20])
	by mx1.FreeBSD.org (Postfix) with SMTP id F22B943FE3
	for <cvs-all@FreeBSD.org>; Fri,  5 Dec 2003 22:54:53 -0800 (PST)
	(envelope-from silby@silby.com)
Received: (qmail 41020 invoked from network); 6 Dec 2003 06:54:52 -0000
Received: from niwun.pair.com (HELO localhost) (209.68.2.70)
  by relay.pair.com with SMTP; 6 Dec 2003 06:54:52 -0000
X-pair-Authenticated: 209.68.2.70
Date: Sat, 6 Dec 2003 00:54:51 -0600 (CST)
From: Mike Silbersack <silby@silby.com>
To: Alan Cox <alc@FreeBSD.org>
In-Reply-To: <200312060545.hB65jWx4095325@repoman.freebsd.org>
Message-ID: <20031206005341.D33930@odysseus.silby.com>
References: <200312060545.hB65jWx4095325@repoman.freebsd.org>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: cvs-src@FreeBSD.org
cc: src-committers@FreeBSD.org
cc: cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/vm vm_mmap.c
X-BeenThere: cvs-all@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: CVS commit messages for the entire tree <cvs-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-all>,
	<mailto:cvs-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/cvs-all>
List-Post: <mailto:cvs-all@freebsd.org>
List-Help: <mailto:cvs-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-all>,
	<mailto:cvs-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 06 Dec 2003 06:54:57 -0000


WHOOOOOOOOOOO HOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

I'm not sure if any has realized it yet, but I think that this may be our
first actual deadlock condition.  This means that we're actually locking
things!

Congrats,

Mike "Silby" Silbersack


On Fri, 5 Dec 2003, Alan Cox wrote:

> alc         2003/12/05 21:45:32 PST
>
>   FreeBSD src repository
>
>   Modified files:
>     sys/vm               vm_mmap.c
>   Log:
>   Fix a deadlock between vm_fault() and vm_mmap(): The expected lock ordering
>   between vm_map and vnode locks is that vm_map locks are acquired first.  In
>   revision 1.150 mmap(2) was changed to pass a locked vnode into vm_mmap().
>   This creates a lock-order reversal when vm_mmap() calls one of the vm_map
>   routines that acquires a vm_map lock.  The solution implemented herein is
>   to release the vnode lock in mmap() before calling vm_mmap() and reacquire
>   this lock if necessary in vm_mmap().
>
>   Approved by:    re (scottl)
>   Reviewed by:    jeff, kan, rwatson
>
>   Revision  Changes    Path
>   1.174     +13 -4     src/sys/vm/vm_mmap.c
>